Computer is derived from a Latin word “computare” which means to “to
calculate” , “to count” , “to sum up” or “to think together” . So, more precisely the word
computer means a "device that performs computation ". According to Wikipedia the
word “Computer" was first used in a book called “the Young man’s gleanings” in 1613.
A computer is a general-purpose electronic device that can be programmed to
carry out a set of arithmetic or logical operations automatically. Since a sequence of
operations can be readily changed, the computer can solve more than one kind of
“A Computer is programmed device with a set of instructions to perform specific
tasks and generate results at a very high speed”.
The progression in hardware representation of a bit of data:
1. Vacuum Tubes (1950s) - one bit on the size of a thumb;
2. Transistors (1950s and 1960s) - one bit on the size of a fingernail;
3. Integrated Circuits (1960s and 70s) – thousands of bits on the size of a
4. Silicon computer chips (1970s and on) – millions of bits on the size of a
The progression of the ease of use of computers:
1. Almost impossible to use except by very patient geniuses (1950s);
2. Programmable by highly trained people only (1960s and 1970s);
3. Useable by just about anyone (1980s and on) to see how computers got
smaller, cheaper, and easier to use.
HISTORY OF COMPUTER
The earliest known tool for use in computation was the abacus, developed in the
period between 2700–2300 BCE in Sumer.
It was initially used for arithmetic tasks.
…dating between 150 to 100 BC, is the world's oldest analog computer
It was believed to be the earliest known mechanical analog computer according
to Derek J. de Solla Price.
It was designed to calculate astronomical positions.
The astrolabe was invented in the Hellenistic world in either the 1st or 2 nd
centuries BC and is often attributed to Hipparchus.
A combination of the planisphere and dioptra, the astrolabe was effectively an
analog computer capable of working out several different kinds of problems in
It was invented by Abi Bakr of Isfahan, Persia in 1235.
It is a calculating instrument used for solving problems in proportion,
trigonometry, multiplication and division, and for various functions, such as
squares and cube roots
It was developed in the late 16th century and found application in gunnery,
surveying and navigation.
It was a manual instrument to calculate the area of a closed figure by tracing
over it with a mechanical linkage.
It was invented around 1620–1630, shortly after the publication of the concept of
It is a hand-operated analog computer for doing multiplication and division.
When John Napier discovered logarithms for computational purposes in the early
17th century, there followed a period of considerable progress by inventors and
scientists in making calculating tools.
In 1623, Wilhelm Schickard designed a calculating machine, but abandoned the
project, when the prototype he had started building was destroyed by a fire in
Around 1640, Blaise Pascal , a leading French mathematician, constructed a
mechanical adding device based on a design described by Greek mathematician
Hero of Alexandria.
In 1837, it was designed as the first design for a modern computer invented by
Charles Babbage, known as the “Father of Modern Computer”
It has expandable memory, an arithmetic unit, and logic processing capabilities
able to interpret a programming language with loops and conditional branching.
It has a memory capacity of less than 1 kilobyte of memory and a clock speed of
less than 10 Hertz.
The input of programs and data was to be provided to the machine via punched
ADA LOVELACE (Augusta Ada Byron)
Pioneer of computer programming
Ada Lovelace became the designer of the first computer algorithm, which had the
ability to compute Bernoulli numbers. Moreover, Lovelace’s work with Babbage
resulted in her prediction of future computers to not only perform mathematical
calculations, but also manipulate symbols, mathematical or not.
Henry Babbage, completed a simplified version of the analytical engine's
computing unit in 1888. He gave a successful demonstration of its use in
computing tables in 1906.
It is considered as the first modern analog computer invented by Sir William
Thomson in 1872.
A mechanical analog computer designed to solve differential equations by
integration using wheel-and-disc mechanisms, was conceptualized in 1876 by
James Thomson, the brother of the more famous Lord Kelvin
The art of mechanical analog computing reached its zenith with the differential
analyzer , built by H. L. Hazen and Vannevar Bush at MIT starting in 1927. This
built on the mechanical integrators of James Thomson and the torque amplifiers
invented by H. W.Nieman.
The principle of the modern computer was first described by mathematician and
pioneering computer scientist Alan Turing
In 1936, the introduction of the formalization of an algorithm, with limits on what
can be computed, and a "purely mechanical" model for computing.
Z3 (Zuse 3)
the world’s first functional program-controlled computer developed by Konrad
Zuse in 1941
S2 COMPUTING MACHINE
considered the first process-controlled computer developed by Konrad Zuse
Z4 (Zuse 4)
the world’s first commercial computer built by Konrad Zuse
the first high-level programming designed in 1946
the first automatic electronic digital computer developed by John Vincent
Atanasoff and Clifford E. Berry in 1942
its design was all-electronic and used about 300 vacuum tubes, with capacitors
fixed in mechanically rotating drum for memory
world’s first electronic digital programmable computing device
built by Max Newman in early February 1943
ENIAC (Electronic Numerical Integrator and Computer)
first electronic programmable computer built in the US
first Turing-complete devices performed trajectory calculations
developed under the direction of John Mauchly and J. Presper Eckert at the
University of Pennysylvania
was huge weighing 30 tons and using 200 kilowatts of electronic power and
contained over 1800 vacuum tubes, 1500 relays and hundred thousands of
resistors, capacitors and inductors
MANCHESTER SMALL-SCALE EXPERIMENTAL MACHINE
also known as Manchester Baby
first stored-program computer
the world’s first general purpose electronic digital computer
was built in Victoria Univ. of Manchester by Frederic C. Williams, Tom Kilburn and
it ran its first program on June 23, 1948
a small scale programmable computer based on Turing’s philosophy
with an operating speed of 1MHz, it was considered as the world’s fastest
VON NEUMANN ARCHITECTURE
known as a model for computer architecture designed in 1946
it allows machine instructions and data to share memory space
It has three major parts: 1. arithmetic logic unit, 2. memory, and 3. instruction
FERRANTI MARK 1
the world’s first commercially available general-purpose computer
become operational in April 1951 and ran the world’s first regular routine office
INTEGRATED CIRCUITS (ICs)
the first conceived the idea of using IC in developing computer is Geoffrey W.A.
the first practical IC was invented by Jack Kilby at Texas Instruments and Robert
Noyce at Fairchild Semiconductor
Kilby was successfully demonstrated the first working integrated example on
Sept. 12, 1958
In Feb.06, 1959, Kilby described his new device as “a body of semiconductor
material wherein all the components of the electronic circuit are completely
While Noyce developed a chip half a year later than Kilby. He solved many
practical problems regarding computers.
the explosion of the commercial and personal use of computers and lead to the
invention of microprocessor
the single-chip microprocessor was the Intel 4004 by Ted Hoff, Federico Faggin
and Stanley Mazor
… and the continuous growth of cellular phones, mobile phones, tablets,
smartphones, laptops and other portable computers and other computing
FEATURES OF COMPUTER
Speed: Computer’s processing speed is measures in a fraction of a second.
Millisecond (Kilo Hertz – KHz): a thousandth of a second
Microsecond (Mega Hertz – MHz): a millionth of a second
Nanosecond (Giga Hertz – GHz): a billionth of a second
Pico second (Tera Hertz – THz): a trillionth of a second
Storage: Computer has mass storage section where we can store large volume of data
for future work.
Reliability: Computer can do its work without making any mistakes and is able to
store data for future use.
Versatile: Computer can do varieties of task such as simple to complex computation.
Diligence: Computer can work for many hours continuously without taking any rest
and without decreasing its accuracy and efficiency.
Automatic: Computer does its work automatically by itself as the instructions were
given by the users.
TYPES OF COMPUTER
Personal computer: it is also known as a Microcomputer. It is a small, single- user
computer based on a microprocessor. In addition to the microprocessor, a personal
computer has a keyboard for entering data, a monitor for displaying information, and a
storage device for saving data.
Workstation: a powerful, single-user computer. A workstation is like a personal
computer, but it has a more powerful microprocessor and a higher-quality monitor.
Minicomputer: a multi-user computer capable of supporting from 10 to hundreds of
users simultaneously. Microcontrollers are mini computers that enable the user to store
data and execute simple commands and tasks. These single circuit devices have
minimal memory and program length but are normally designed to be very good at
performing a niche task. Many such systems are known as embedded systems.
Mainframe: a powerful multi-user computer capable of supporting many hundreds or
thousands of users simultaneously.
Supercomputer: an extremely fast computer that can perform hundreds of millions of
instructions per second. It was the fastest and the most expensive computers. These
huge computers are used to solve very complex science and engineering problems.
Supercomputers get their processing power by taking advantage of parallel processing;
they use lots of CPUs at the same time on one problem. A typical supercomputer can do
up to ten trillion individual calculations every second. Ex. K Computer, Columbia and
Server Computer: Servers are a step under supercomputers, because they don't focus
on trying to solve one very complex problem, but try to solve many similar smaller
ones. A server is a central computer that contains collections of data and programs.
Also called a network server, this system allows all connected users to share and store
electronic data and applications. Two important types of servers are file servers and
ADVANTAGES OF COMPUTER
Speed up work efficiency
Wastage of time and energy
Large and Reliable Storage Capacity
Violation of Privacy
Connection with Internet
Impact on environment
Great Educational Tool
Leisure and Entertainment
USES OF COMPUTER
Working from Home
Chatting and Social
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